Terpenoid compounds are a class of compounds formally assembled from terpene building blocks. Naturally occurring terpenoids constitute one of the largest classes of natural products compounds. Such terpenoids have significant commercial value in the perfume and flavoring industries and as starting materials for the chemical industry. Many members of the terpenoid class are biologically active, with notable compounds having antibacterial or antifungal activity; this potential for biological activity has attracted the interest of the pharmaceutical industry.
Terpenoids of commercial interest often are not naturally occurring, but rather derivatives which commonly require regioselective or stereoselective functionalization at allylic or non-activated carbon-hydrogen bonds of the parent terpene. This type of chemical transformation can be difficult to carry out by conventional methods because the highly reactive chemical oxidizing agents typically used lack selectivity and may preferentially attack other carbon-hydrogen bonds and reactive functional groups, such as olefinic double bonds commonly present in terpenes.